EP0903555B1 - Fin for heat exchanger and method for making holes in such a fin - Google Patents

Description

The invention relates to a rib for a heat exchanger according to claim 1 as well as one Method for the production of ribbed passages in such ribs according to claim 3.

Such a rib is known from DE 34 23 746 A1. The Rib is provided with several passages, each one Having collared parallel to the passage axis collar. Each collar has in the upper area on opposite Pages each a right angles outward projecting, the Draft partially circumferential and thus flanking support edge on. The support edges serve as a support surface for positioning the corresponding adjacent rib.

Such a method is known from CH 428 323. to Making the rib are in a flat ribbed sheet for each passage cuts introduced. In a following Process step, the cut edges to a Collar set up, taking on opposite sides respectively a small, triangular flap parallel to the rib plane is turned off to the outside.

Another rib and another method are from the DE 44 04 837 A1 known. For a uniform rib division for the ribs of a rib / tube block of a heat exchanger to achieve, are the tubes of the rib / tube block receiving Passage of the ribs with spacers in the form of on the circumference of the passages distributed pronounced noses educated. To make the passages of the ribs in a first step from a corresponding flat ribbed sheet in the area of each passage through openings punched out, at the same time lobes cut free to be in a subsequent one Process step serving as spacers nose be embossed. Subsequently, the rags including outwardly shaped noses by means of stamps and stenciled and tipped and finally the entire collar including flaps and noses completely pulled through. When punching the passage openings arises a punching waste, by means of separate operations must be removed to prevent him from using the tool contaminated. Such additional operations are in particular the blowing out of the punching waste by means of Compressed air nozzles.

The object of the invention is a rib of the aforementioned To create a kind of good, with ease of manufacture and robust spacer functions to achieve a uniform rib division as the prior art allows. The object of the invention is also a method to create the rib passages to provide in the ribs

For the rib is the task by the features in the characterizing part of Claim 1 solved. According to one embodiment of the invention can the respective passage so well for round as well as flat oval or flat tubes be designed. By the support edge is a further improved Support of the above the rib lying, adjacent Rib created so that a safe adherence to the uniform rib pitch of the ribs / tube block achievable is. For flat or flat-oval tubes, each passage shows preferably two on opposite longitudinal sides of the By pulling arranged support edges, which are correspondingly opposite are turned off to the outside. The through the support edges formed flat bearing surface runs parallel to Ribs level. By providing the at least one additional Stützrandes it is possible in the production of Punctures on the punching of passage openings - like this in the prior art the case is - to renounce and the Making passages on the basis of simple separating cuts.

In an embodiment of the invention, the at least one support edge with at least one coplanar protruding outward, ear-like Provided tab. The ears-shaped flap increases the flat bearing surface for each adjacent rib, so that a further improved blocking of the ribs / tube block is achievable.

For the procedure becomes the task by the features in the characterizing Part of claim 3 solved. at the method according to the invention created no trash, there no punching to create passage openings is needed. The passages are rather on the base created the simple cuts. There is no punching waste accumulates, eliminates the necessary operations for removal and disposal of punching waste. Thus, a cheaper one Production of rib passages achievable. Also the pressing tools can be made simplified since No action needs to be taken to remove achieve the punching waste from the punching areas.

In an embodiment of the method, the separating cut to his opposite ends to form ear-like Curved tabs. The curved course of the separating cuts Ensures the formation of ear-like tabs, that at the subsequent forming stages no tearing of the ribbed plate at the level of the separating cut. Thus an improved manufacturability of Rippendurchzüge is achieved.

Fig. 1

zeigt in einer Draufsicht auf einen Teil einer Ausführungsform einer Rippe einen Rippen/Rohrblock eines Wärmeübertragers,

Fig. 2a

ein ebenes Rippenblech im Bereich eines Trennschnittes zur Herstellung eines Durchzuges für die Rippe nach Fig. 1,

Fig. 2b

einen weiteren, an den Herstellungsschritt nach Fig. 2a anschließenden Herstellungsschritt zur Schaffung des Durchzuges,

Fig. 3a und 3b

Schnittdarstellungen entlang der Schnittlinie III-III in den Fig. 2a und 2b des Rippenbleches in den Herstellungsschritten nach den Fig. 2a und 2b,

Fig. 4a

einen weiteren Herstellungsschritt zur Erzielung des Durchzuges in der Rippe nach Fig. 1,

Fig. 4b

den fertiggestellten Durchzug der Rippe nach Fig. 1,

Fig. 5a

eine Schnittdarstellung des Umformvorganges für den Herstellungsschritt nach Fig. 4a entlang der Schnittlinie V-V in den Fig. 4a und 4b,

Fig. 5b

eine Schnittdarstellung entlang der Schnittlinie V-V in den Fig. 4a und 4b des letzten Herstellungsschrittes zur Erzielung des Durchzuges für die Rippe nach Fig. 1,

Fig. 6 bis 10

verschiedene Herstellungsschritte zur Herstellung einer Rippe ähnlich Fig. 1, bei der Stützränder der Durchzüge mit ohrenartigen Laschen versehen sind.

Hereinafter, preferred embodiments of the invention will be described and illustrated with reference to the drawings.

Fig. 1

shows in a plan view of a part of an embodiment of a rib a fin / tube block of a heat exchanger,

Fig. 2a

a flat ribbed plate in the region of a separating cut for producing a passage for the rib according to FIG. 1,

Fig. 2b

a further production step subsequent to the production step according to FIG. 2a for the creation of the passage,

Fig. 3a and 3b

Sectional views along the section line III-III in FIGS. 2a and 2b of the ribbed plate in the production steps according to FIGS. 2a and 2b.

Fig. 4a

a further production step for achieving the passage in the rib according to FIG. 1,

Fig. 4b

the completed passage of the rib of Fig. 1,

Fig. 5a

4 is a sectional view of the forming process for the production step according to FIG. 4a along the section line VV in FIGS. 4a and 4b, FIG.

Fig. 5b

1 is a sectional view along the section line VV in the Fig. 4a and 4b of the last manufacturing step to obtain the passage for the rib of FIG. 1,

Fig. 6 to 10

Various manufacturing steps for producing a rib similar to FIG. 1, are provided in the support edges of the passages with ear-like tabs.

Ribs 1, 1a, as shown in Figs. 1 and 10 fragmentary are part of a rib / tube block for a Heat exchanger, especially for use in one Motor vehicle, wherein a plurality of parallel to each other aligned ribs 1, 1a each with a plurality of provided in parallel juxtaposed passages 3, 3a are a variety of parallel in a row next to each other take up running pipes. The pipes are shown at Embodiment designed as flat oval tubes, whereby the passages 3, 3a corresponding to identical are designed. The composite of ribs 1, 1a and pipes Ribs / tube block is mechanical in a conventional manner joined, wherein the passages 3, 3a of the superimposed Ribs 1, 1a each tightly enclose a tube. The passages 1, 1a of the ribs 3, 3a protrude respectively rectified from the associated rib and form for the overlying rib 1, 1a spacers, so that a achieved even rib pitch of the ribs / tube block becomes. The basic structure of a rib / tube block, such as he has been previously described, including the mechanical Fuegung of the ribs / tube block is detailed in the DE 44 04 837 A1 and disclosed by drawings, so that reference is made to this document for a more detailed explanation becomes.

The rib 1 has, according to FIGS. 1, 4b and 5b, a flat ribbed plate 2, whose longitudinal edges each with one Rim groove 5 are provided. Along the flat ribbed plate 2 are aligned at regular intervals parallel to each other Passages 3 provided, the passage opening to the Outer contour of flat oval tubes is adapted. Between adjacent passages 3 are known gill fields 4, for further explanation also to the DE 44 04 837 A1 is referenced. The passages 3 are identical designed to each other. Each passage 3 has a circumferential, perpendicular to the rib plane defining Rippenblech 2 parked on one side collar 9, on in the area of the opposite longitudinal sides of the collar 9 connect two support edges 6 that are parked at right angles to the outside. The surface of the support edges 6 runs parallel to the rib plane formed by the ribbed sheet 2. in the Transition region between the collar 9 and the support edges. 6 are on both sides of the collar 9 three in even Interspersed noses 7 stamped. The Noses 7 are analogous to those described in DE 44 04 837 A1 Nasen so pyramideneckförmig designed that they in the Level of the support edges 6 a triangular cross-section form. The noses 7 are on the opposite longitudinal sides each passage 3 mirror-symmetrical to a central longitudinal plane each passage 3 arranged so that each longitudinal side the passage 3 and thus each support edge 6 respectively three lugs 7 are assigned. The noses 7 have next to one Spacer function, which in itself from DE 44 04 837 A1 is already known, for the two support edges 6 a stiffening function on, since they for the support edges 6 a forming web-like support function.

As can be seen from Fig. 5b, the upper edges of the Noses 7 in a common flight with the support edges 6, so that through the upper edges of the noses 7 and through the Support edges 6 formed bearing surface parallel to the ribbed plate 2 are aligned and the support surface for in the assembled Condition respectively overlying and identical form shaped rib 1.

The rib 1a of Fig. 10 substantially corresponds to the rib 1, as previously described. Same parts of the Rib 1a are therefore denoted by the same reference numerals, only with the addition of the letter a. The only Difference in the rib 1a to the rib 1 of FIG. 1 it is that the passages 3a of the rib 1a on diagonally opposite End portions of the opposite support edges 6a each have an ear-like tab 10 which is coplanar protrudes to the support edge 6a to the outside. The ear-like flap 10 has manufacturing causes, as described below will be.

First of all, however, the method of manufacturing the passages 3 of the rib 1 will be described. For the production of passages 3 within the rib 1, a separating cut 8 (FIGS. 2 a and 3 a) is introduced in the ribbed plate 2 at the level of the respective tube spacing and thus the subsequent positioning of the passages 3 transversely to the longitudinal axis of the ribbed plate 2, which is achieved by a suitable cutting tool is achieved with simultaneous support of the ribbed plate 2. In a further method step, according to FIGS. 2b and 3b, the supporting edges 6 and the lugs 7 are created. For this purpose, a perpendicular to the ribbed plate effective punch S _{1 is} provided as a corresponding forming tool, which cooperates with a die, not shown. The die S ₁ has a blade-like shape with a cross section which corresponds to the profile of the support edges 6 in FIG. 2 b. The embossing punch S ₁ also has in each case laterally such embossing edges that the lugs 7 are embossed by the forming step together with the bending of the supporting edges 6. After the process step according to FIGS. 2 b and 3 b, the supporting edges 6 protrude upward at right angles to the rib plane formed by the ribbed sheet 2. The reason of each triangular nose in cross-section 7 extends according to FIG. 3b at an acute angle to an underside of the ribbed plate 2 to the respective support edge 6 inwardly and upwardly. The cut edges formed by the separating cut 8 are thus exposed to the formation of the support edges 6 upwards and widened. The widening must be so gentle that no tearing of the separating cut 8 occurs at the opposite, end-side edge regions.

In a further method step, a further widening of the passage opening takes place, whereby a circumferential collar 9, which in this process step is tilted obliquely upward and thus tapers conically upwards, is created by a further embossing punch S ₂ which is enlarged in width relative to the embossing punch S ₁ , For this purpose, the embossing punch S _{2 is provided} with a correspondingly elliptical and tapered embossing contour. By the stamper S ₂ , a transformation takes place such that additional material of the rib plate 2 is pressed obliquely upward in the region of the passage opening, resulting in the circumferential collar 9 below the lugs 7 and the support edges 6. In this intermediate stage, the collar 9 tapers towards the free end of the passage opening and the two support edges 6 protrude at right angles to the collar obliquely upwards and outwards. In a further method step, the final contour of the passage 3 is achieved by means of a further widened in cross-section punch S ₃ , wherein the collar 9 is pulled through such that its peripheral wall is perpendicular to the rib plane turned up. This documented with reference to FIGS. 4b and 5b process step includes the completed passage, wherein the support edges 6 each project at right angles to the collar 9 to the outside.

The method for producing the passages 3a from the ribbed sheet 2a of the rib 1a according to FIGS. 6 to 10 corresponds to FIG essentially the production method described above, so that only following the differences to the already described production process is received. In both manufacturing processes after completion of the Passages 3, 3a the further completion of the ribs 1, 1a achieved by the gill panels 4, 4a and the edge grooves 5, 5a are impressed accordingly.

Only difference in the production of the passages 3a of the Rib 1a is that in the first process step a different designed separating cut 8a is made. This cut 8a has in addition to its rectilinear middle Area two forehead areas, in which the separating cut under Forming ear-like tabs 10 hook-like curved in the plane of the rib plate 2a extends. Despite the two Curvatures in the area of the opposite end areas is the separating cut 8a integral and continuous, wherein the separating cut 8a by means of a correspondingly shaped Cutting tool created in a single cutting process becomes. The subsequent embossings correspond with reference to FIGS. 2b, 3b, 4a, 5a and 4b, 5b shown Process steps for the production of the passage 3, wherein the ears-like tabs 10 each associated with a support edge 6a are coplanar and projecting outwards to this extend. By the hook-like curvature of the separating cut 8a in its opposite forehead areas becomes tearing of the ribbed plate 2a by corresponding notch effects, as in the embodiment of FIGS. 1 to 5b could occur avoided, since the ears-like tabs 10th in the embossing the Prägeschritte according to FIGS. 7 and 8 no major stress effects in the main load directions arise. In the finished Form of the passages 3a according to FIGS. 8 to 10 form the tops of the ear-like tabs 10 additional Support surfaces, a further improved edition of the overlying Enable rib.

In a further embodiment are several cuts for the creation of the subsequent durchzuziehenden cutting edges provided in such a way to each other are positioned so that no cutting waste.

Claims (7)

1. Fin (1, 1A) for a heat exchanger comprising a matrix of fins and tubes, made up of tubes and fins extending transversely thereto, with several insertion slots (3, 3a) which receive the tubes of the fin/tube matrix in the assembled state, each insertion slot (3, 3a) having spacers to obtain a uniform positioning of the fins relative to each adjacent fin and in which every insertion slot (3, 3a) has a collar (9) with at least one outwardly angled and at least partially circumferential supporting rim (6, 6a) perpendicular to the insertion axis forming a flat bearing surface for the adjacent fin (1, 1a), characterised in that noses (7, 7a) of a pointed pyramid shape are punched into the transition region between collar and supporting rim so that they form a triangular cross section in the plane of the supporting rim.
2. Fin as claimed in claim 1, characterised in that the at least one supporting rim (6a) is provided with at least one coplanar, outwardly projecting ear-type tab (10).
3. Method of producing fin insertion slots in fins for heat exchangers of the type outlined in the generic part of claim 1, in which a collar forming a respective insertion slot (3, 3a) is made by bending in a flat plate to produce at least one outwardly angled supporting rim (6, 6a) perpendicular to the insertion axis, produced by firstly making at least one incision (8, 8a) in the flat fin plate (2, 2a),
   characterised in that the cut edges formed by the incision are then provided with noses (7, 7a) of a pointed pyramid shape in the transition region between collar and supporting rim, which are bent towards the collar (9, 9a) so that they form a triangular cross section in the plane of the supporting rim.
4. Method as claimed in claim 3, characterised in that the incision (8, 8a) is curved at its oppositely lying ends to form ear-type tabs (10).
5. Method as claimed in one of claims 3 or 4, characterised in that at the same time as the noses (7, 7a) are punched, the cut edges are opened out to form the at least one supporting rim (6, 6a) and the collar (9, 9a) is formed behind the supporting rim (6, 6a) - as viewed in the bending direction - by making another bend, the supporting rim (6, 6a) being disposed perpendicular to the collar (9, 9a).
6. Method as claimed in claim 5, characterised in that the collar (9, 9a) is made in two consecutive process steps, whereby the collar (9, 9a) is placed in an angled position relative to the fin plate (2, 2a) during the first step and bent into the end position perpendicular to the fin plate (2, 2a) during the second step.
7. Heat exchanger made up of a matrix of fins and tubes comprising tubes and fins extending transversely thereto, having the fins as claimed in claim 1 or 2.

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